How to Protect Muscle While Taking GLP-1 Medications

As GLP-1 medications continue to transform the weight loss landscape, more patients are seeing dramatic changes on the scale — but experts say the conversation should not stop there. While these medications can be highly effective for reducing body weight, they can also significantly suppress appetite, making it harder for people to consume enough protein and calories to preserve lean muscle mass during the process.

According to Rhode Island certified fitness trainer Denise Chakoian, owner of Core Cycle.Fitness.Lagree, maintaining muscle is one of the most overlooked yet important parts of long-term health and sustainable weight management. Muscle plays a critical role in metabolism, strength, balance, energy levels and overall physical function, meaning rapid weight loss without resistance training and proper nutrition can leave patients feeling weaker rather than healthier.

In this Q&A, Chakoian discusses the difference between weight loss and body composition, warning signs of muscle loss and realistic ways patients can incorporate strength training into their routines while taking GLP-1 medications.

GLP-1 medications have helped many people lose significant amounts of weight, but there’s growing concern about muscle loss during that process. Why is preserving lean muscle so important for long-term health, metabolism and even how people feel physically day to day?

Denise Chakoian: Muscle is essentially your body’s metabolic engine. The more you have, the more calories you burn even at rest, which makes it far easier to maintain weight loss over time. Beyond metabolism, lean muscle supports your joints, improves balance, and reduces the risk of injury and chronic pain as you age. People with more muscle mass tend to feel stronger, more energetic and more capable in everyday life, whether that’s carrying groceries or playing with their kids. Losing muscle during weight loss can leave someone lighter on the scale but still feeling sluggish, weak and, frankly, not much better than before.

Many patients assume that losing weight automatically means becoming healthier. Can you explain the difference between simply losing weight and improving body composition, and why that distinction matters for people using GLP-1 medications?

DC: Losing weight just means the number on the scale goes down, but that number doesn’t tell you whether you lost fat, muscle or water. Body composition is really about the ratio of fat to lean mass, and improving that ratio is what actually drives better health outcomes like lower blood sugar, stronger bones and more functional strength. Someone could lose 30 pounds on a GLP-1 medication, but if a third of that was muscle, they’ve done themselves a partial disservice. The goal should be losing fat while protecting or even building muscle, which is a very different and more intentional process.

Because these medications can dramatically reduce appetite, some people may not be eating enough protein or calories overall. What are some warning signs that someone could be losing too much muscle instead of primarily losing fat?

DC: One of the clearest signs is feeling unusually weak or fatigued. For example, things like struggling to climb stairs, open jars or carry things that used to feel easy. If someone notices they’re losing weight quickly but their clothes don’t seem to fit differently in a flattering way, that can be a clue that muscle is going along with the fat. Feeling constantly cold, mentally foggy or having a hard time recovering from even light activity are also red flags worth paying attention to. Anyone experiencing these symptoms should bring them up with their doctor and consider whether they’re getting enough protein and resistance exercise.

For patients who may feel intimidated by strength training or have never exercised regularly before, what are some realistic and approachable ways to start building resistance training into their routine while taking a GLP-1 medication?

DC: The best place to start is with body weight movements at home. Things like squats, wall push-ups and sit-to-stands from a chair are surprisingly effective and require zero equipment or gym membership. Starting with just two days a week for 20 minutes takes the pressure off and makes it feel manageable rather than overwhelming. Many people find it helpful to think of it less as “working out” and more as practicing movements, because that framing removes the all-or-nothing mindset that leads to giving up. As strength and confidence build naturally over a few weeks, adding resistance bands or eventually light weights becomes something people actually look forward to rather than dread.

The scale can become a major focus during weight loss journeys, but you emphasize tracking strength and muscle retention too. What are healthier or more meaningful ways patients can measure progress beyond just the number on the scale?

DC: Tracking how much weight you can lift or how many reps you can complete is one of the most motivating metrics because it almost always goes up, even when the scale stalls. How your clothes fit, particularly around the waist versus the shoulders and thighs, tells a much more honest story about body composition than any single number. People also tend to notice improvements in sleep quality, energy levels and mood long before the scale reflects meaningful change.